Synergistic antibacterial activity of chitosan-polyethylene glycol nanocomposites films containing ZIF-8 and doxycycline

Abstract

Background Antibiotic resistance is a growing global threat due to antibiotic overuse and limited treatment options. Multidrug-resistant bacteria, like Staphylococcus aureus and Escherichia coli , increase infection complexity and mortality. This study explores nanocomposite films of ZIF-8 nanoparticles and Doxycycline (Dox) to enhance antibacterial efficacy. In this study, nanocomposite films composed of chitosan (CS) and polyethylene glycol (PEG), incorporating zeolitic imidazolate framework-8 (ZIF-8) nanoparticles and DOX, were developed. These films were characterized by their morphological, mechanical, antibacterial, and drug-release properties. Antibacterial efficacy was evaluated using disk diffusion, broth microdilution, and checkerboard assay methods to determine MICs and potential synergistic effects. Results The nanocomposite films demonstrated flexibility, semi-transparency, and a yellowish-brown hue, with films containing ZIF-8 nanoparticles being thicker (79 ± 0.2 μm) than those without (54 ± 0.5 μm). The tensile strength was enhanced with the incorporation of ZIF-8, peaking at 53.12 MPa for the CS-PEG-G-10% DOX-4% ZIF-8 film. XRD analysis confirmed the crystallinity of the ZIF-8 and DOX, with distinct peaks observed for each material. The drug release studies revealed an initial burst followed by sustained release, with higher release rates in acidic environments compared to neutral and alkaline media. The CS-PEG-G-10% DOX-4% ZIF-8 nanocomposite film demonstrated significantly higher antibacterial activity, achieving the lowest MIC values, particularly against S. aureus (22.5 mm inhibition zone) compared to E. coli (14 mm inhibition zone). Additionally, a notable synergistic effect was observed between CS-PEG-G-10% DOX and CS-PEG-G-10% DOX, with FICI values below 0.5. Conclusions The CS-PEG-G-10% DOX-4% ZIF-8 nanocomposite exhibits enhanced antibacterial efficacy and optimal properties, positioning it as a strong candidate for developing effective treatments against multidrug-resistant pathogens.

Synergistic Antifungal Efficacy of Eugenol‐Loaded Nanocapsules Combined With Itraconazole Against Trichophyton mentagrophytes

“…Therefore, the current findings not only support the use of nano‐eugenol as a systemic adjuvant but also point to its potential as an effective component in topical dermatological products (Jamiri et al. 2025 ).…”

“…Additionally, nanoencapsulation can enhance the bioavailability and controlled release of bioactive compounds, making them ideal for treating superficial fungal infections like dermatophytosis. Therefore, the current findings not only support the use of nanoeugenol as a systemic adjuvant but also point to its potential as an effective component in topical dermatological products (Jamiri et al 2025).…”

“…This approach addresses the challenges of rapid metabolism and poor solubility associated with conventional eugenol formulations, thereby enhancing its antifungal performance when combined with Itraconazole (Jamiri et al. 2025 ; Namdar et al. 2024 ; Pateiro et al.…”

“…Additionally, nanoencapsulation can improve the stability of bioactive compounds, enhancing their therapeutic efficacy. This approach addresses the challenges of rapid metabolism and poor solubility associated with conventional eugenol formulations, thereby enhancing its antifungal performance when combined with Itraconazole (Jamiri et al 2025;Namdar et al 2024;Pateiro et al 2021).…”